Sewing-machine mechanism



R. K. HOHMANN SEWING MACHINE MECHANISM Dec. 28 1926.

Filed August '7, 1923 23M (i /5 M ATTORNEY INVENTOR W )2 $0M Patented Dec. 28

'UNETED STATES PATENT RZCZEARD K. HOHMANN, OF PER- MACHINE COMPANY, OF PERU, IN

U, INDIANA, ASSIGNGR IO HOHIv'IANN SEVING DIANA, A COROBATION OF INDIANA.

SEWING-MACHINE MECHANISM.

Application filed August 7, 1923. Serial No. 656,185.

The general object of my present invention employ-ed is several employed now in general use.

The various features 0 in the high speed times larger proved loop forming hook sewing machines, igh speed hich the thread bobbin than those sewing machines it novelty which characterize my invention are pointed out with particularity in the and forming a part of this specificat a better understanding of ever, its advantages tained with its use, reference shou to the accompanying tive matter in which I hav the inventi and drawings and claims annexed to ion for on ho wspecific objects atld be made descripe illustrated and described a preferred embodiment of my invention.

Of the drawings: Fig. 1 is an end el chine head;

evat

Fig. 2 is an end elevation of a po the apparatus shown 111 Fig. 1, tak

larger scale and with parts in section;

ion ot a sewing martion of en on a broken away and Fig. 3 is a section on the line 3 -3 of Fig.

2; and Fig. on the line 4.& of

base or bed A.

the rotary take'up mec bar C and the presser A is located the rot is carried by a shaft lutions for each complete re the needle bar C.

The hook ring E,

l is a section of the hook ring taken Fig. 3; and Fig. 5 is a partial section taken on the line 5-5 or Fig. 2.

bar

ary h n as shown,

represents the head of ovided with the usual head A, are hanism B, the needle D. Beneath the bed hook ring E, which and makes two revociprocation of is formed in two parts i. e. an annular rim, or body 6, and At lts front end, the

a spider member 6. ring body flange E,

c'is provided with an which with a rim portio internal n of the spider member 6, and the inner surface of the ring body 0 for the shuttle away at one portion the loop taking hook E 13* in front of the hook E fiector element is and extends across t ring is provided wit of its periphery and the usu secured .h h a thread guar forms a bearing groove E G. The hook ring E 18 cut to form al notch A thread deto the hook ring e notch E The hook d finger E the form and purpose of whichis hereinafter described. I

The shuttle G is formed with a peripheral bearing rim G whiehis received in the ring bearing groove E and the shuttle is also provided along a portion of its periphery with a radial flange G projecting in front of the hook ring and formed with shoulders G and G which cooperate in the usual manner with av stop lug A attached to the bed A of the machine and holding the shuttle against rotative movement other than that required to permit the thread to pass between the shuttle and the stop A in each loop forming operation. Detachably mounted in the shuttle G is a bobbin casing element H in which the bobbin H is held, and which unites with the shuttle member G to form a. complete bobbin housing formin g element about which the thread loop is passed in each stitch forming operation.

The thread guard finger E carried by the hook ring, in the particular construction illustrated, is in the form of an integral portion of the hook ring spider element 6 which projects to the rear from the front end of the notch having reference to the direction of rotation 01"" the hook ring E which is counter-clockwise. The finger E" which is tapered, lies back of the shuttle bearing rim G, and the point of the finger E moves in close proximity to the rearside ot' the hearing rim along a circular path, the diameter of which is appreciably smaller than the di ameter of the bearing rim as is clearly shown in the drawings. The outer side of the finger E slopes outwardly from the point oi gaged and protected by the finger IE will" be apparent to those skilled in the art from the showing in Figs. 2 and 3, wherein I indicates the front limb, and L the rear limb' of the thread loop.

As before stated, the invention is of special utility in the case of a high speed big bobbin sewing machine, employing a rotary take-up mechanism, such as the machine illustrated which is designed to make about four thousand stitches'a minute and to receive bobbin H holding about 265 yards of No. cotton thread. In a machine of this sort the relatively large take-up movement required can best be obtained with a rotary take-up mechanism which draws up the frontlimb I ofthe loop very rapid.- ly after the loop is cast off the -hook E With the described arrangement, the point of the finger E is angularly in advance of the point of the hook E and the thread loop is drawn away from the finger E and above the path of the rotary hook before the latter comes into loop taking position. The tendency of the thread tojam between the shuttle bearing rim G and the walls of the bearing groove E in the ringE, which it is the primary purpose of the invention to prevent, might: be substantially eliminated by elongatingthe notch E so that the front end of the notch would be farther away from the point of the hook E but this involves a decreased amount of bearing surface between the hook ringE, and the shut tle bearing rim G, which, as those skilled in the art'known, must also be notched angularly in advance of the shoulder G and such decrease in bearing surface is objectionable as it tendsto looseness in the shut tle mounting with resulting undesirable lost mot-ion, and-play of the shuttle in its bearmg.

While in accordance with the provisions of the statutes I have illustrated and: described the best from of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the-apparatus disclosed without-departing from the'sp'irit of my invention as setforth in the appended claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

Having now described my invention, what I claim as new, and desireto secureby Lettcrs Patent, is;

1. In a rotary hook sewing machine comprising a rotating hook member formed with an internal bearing groove, and with a loop taking hook and with a peripheral notch alongside and in front of said hook, and a non rotating shuttle formed with a peripheral bearing rim received in said groove, the improven'ient which consists in a thread guard finger carried by said hook member and projecting rearwardly from the front end of the notch, having reference to the direction of rotation of the hook memher, and terminating angularly in advance of the point of the loop taking hook, in a point moving in close proximity to the rear side of said bearing rim along a circular path of smaller diameter than said bearing rim.

In a rotary hook sewing machine comin close proximity tothe rear side of said bearing rim along a circular path of smaller diameter than said bearing rim, the outer side of said linger sloping outwardly from the point thereof toward the periphery of said bearing: rim.

3. In a high speed big bobbin rotary hook sewing machine comprising a rotating hook member formed with an internal bearing groove and with a loop taking hook and with a peripheral notch alongsideand in front of said hook and a non rotating shuttle formed with a peripheral bearing rim receivedin said groove and a rotary take up mechanism adapted to draw the thread loop above said hook member before the latter completes a loop drawing revolution, the improvement which consistsin a thread guard finger carried by said hook member and projecting rearwardly from the front end of the notch having reference to the direction of rotation of the hook member and terminating angularly in. advance of the point of. the loop taking hook and com;- prising an operative portion at the rear of said groove and less remote from the. axis of the hook member than the bottom of said groove.

Signed at New York city in thecounty of New York andState. of New York this 3 day of August A. D. 1923.

RICHARD K. HOHMANN. 

